This invention relates to the art of making snow for ski resorts and the like. More particularly, it relates to improvements in apparatus for evenly distributing man-made snow with minimal operator involvement.
Though the art of snow-making has been known for several decades, the application of the art to the business of making snow at ski resorts has presented many challenges. While it's a relatively simple matter to combine water and compressed air in such a manner as to produce, under controlled conditions, a uniform blanket of man-made snow, it is considerably more difficult to produce such uniformity on a mountain top where the terrain is steep, the winds shift and the temperature and humidity frequently undergo the type of change that affects the moisture content of the snow produced. For example, it is not uncommon to discover in the morning following a night of snow-making that, as a result of a wind shift or unexpected temperature rise, most of the snow made has either been blown into the woods adjacent the ski trail intended for the deposit, or become so laden with moisture that the "slushy" desposit has frozen to a treacherous mass that, prior to skiing, must either be pulverized or covered over. In either case, most of the cost of the previous night's snow-making operation has been wasted.
To minimize waste of man-made snow, many ski resorts maintain large crews of equipment operators whose job it is to travel the mountainside and make adjustments, as needed, to the "snow-guns", i.e. the snow-making devices which combine water and compressed air in such a manner as to produce a spray of ice crystals. Often, the direction of the spray from these guns must be readjusted to compensate for changes in wind direction and speed, as well as changes in the moisture content of the snow (which determines its weight and, hence, how far it can be projected). Also, the ratio of the water and compressed air must be adjusted, from time-to-time, to compensate for changes in temperature and relative humidity; otherwise, the snow consistency will be either too wet or too dry. As the ambient temperature increases, for example, less water is needed to achieve a nominal snow consistency or quality.
In the commonly assigned U.S. patent application Ser. No. 470,955, filed on Jan. 26, 1990 in the names or H. R. Ratnik et al., there is disclosed an automated snow-making system that significantly reduces the labor costs associated with making the adjustments referred to above. Such a system comprises apparatus for remotely controlling the water/compressed air ratio supplied to the snow-guns, as well as the direction in which the guns project snow. To control the latter, the guns are mounted on a support which, in turn, is rotatably mounted for rotation about horizontal and vertical axes so as to adjust both the elevation and azimuth of the snow-gun nozzle. A pair of remotely controllable motors functions to rotate the gun support about these axes of rotation to provide a nominal aiming position.
While the gun-aiming components of the above-noted system facilitates a nominal setting of the direction in which the gun output is directed, it is often desirable to make frequent azimuth adjustments to compensate for changes in wind speed and direction, as well as temperature and relative humidity changes which, as noted above, affect the weight of the snow. Also, even when the weather conditions are stable, it is usually desirable to make frequent azimuth adjustments so that the snow does not pile up in a relatively small area. As an alternative to making these frequent adjustments, some system operators prefer to allow the snow to pile up for some time and later spread the snow with snow-grooming equipment in order to provide a more uniform snow coverage. Whether making frequent aiming adjustments of the snow-guns, or using heavy equipment to more evenly spread the snow after it has piled up, both of thes approaches to the problem of achieving uniform coverage require the involvement of human forces and/or the use of costly equipment.